Debt - Maximum and Average Outstanding, Weighted Average Interest Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Maximum balance:
Federal Home Loan Bank advances and Fed Funds	$ 186,401	$ 180,025
Federal Reserve Bank	5,000	0
Fed Funds lines of credit	5,000	21,016
Average balance:
Federal Home Loan Bank advances and Fed Funds	93,653	96,044
Fed Funds lines of credit	$ 318	$ 5,286
Weighted average interest rate:
Federal Home Loan Bank advances and Fed Funds (as a percent)	2.61%	2.02%
Federal Reserve Bank (as a percent)	2.96%	0.00%
Fed Funds lines of credit (as a percent)	2.09%	1.93%
Federal Reserve Bank, Advances, Activity for Year, Average Balance Outstanding	$ 167	$ 0
Subordinated note
Average balance:
Subordinated note	$ 10,000	$ 10,000
Weighted average interest rate:
Subordinated note (as a percent)	6.50%	6.50%
Subordinated note | Maximum
Maximum balance:
Subordinated note	$ 10,000	$ 10,000